xref: /linux/drivers/rtc/rtc-rs5c313.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * Ricoh RS5C313 RTC device/driver
3  *  Copyright (C) 2007 Nobuhiro Iwamatsu
4  *
5  *  2005-09-19 modifed by kogiidena
6  *
7  * Based on the old drivers/char/rs5c313_rtc.c  by:
8  *  Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
9  *  Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
10  *
11  * Based on code written by Paul Gortmaker.
12  *  Copyright (C) 1996 Paul Gortmaker
13  *
14  * This file is subject to the terms and conditions of the GNU General Public
15  * License.  See the file "COPYING" in the main directory of this archive
16  * for more details.
17  *
18  * Based on other minimal char device drivers, like Alan's
19  * watchdog, Ted's random, etc. etc.
20  *
21  *	1.07	Paul Gortmaker.
22  *	1.08	Miquel van Smoorenburg: disallow certain things on the
23  *		DEC Alpha as the CMOS clock is also used for other things.
24  *	1.09	Nikita Schmidt: epoch support and some Alpha cleanup.
25  *	1.09a	Pete Zaitcev: Sun SPARC
26  *	1.09b	Jeff Garzik: Modularize, init cleanup
27  *	1.09c	Jeff Garzik: SMP cleanup
28  *	1.10    Paul Barton-Davis: add support for async I/O
29  *	1.10a	Andrea Arcangeli: Alpha updates
30  *	1.10b	Andrew Morton: SMP lock fix
31  *	1.10c	Cesar Barros: SMP locking fixes and cleanup
32  *	1.10d	Paul Gortmaker: delete paranoia check in rtc_exit
33  *	1.10e	Maciej W. Rozycki: Handle DECstation's year weirdness.
34  *      1.11    Takashi Iwai: Kernel access functions
35  *			      rtc_register/rtc_unregister/rtc_control
36  *      1.11a   Daniele Bellucci: Audit create_proc_read_entry in rtc_init
37  *	1.12	Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
38  *		CONFIG_HPET_EMULATE_RTC
39  *	1.13	Nobuhiro Iwamatsu: Updata driver.
40  */
41 
42 #include <linux/module.h>
43 #include <linux/err.h>
44 #include <linux/rtc.h>
45 #include <linux/platform_device.h>
46 #include <linux/bcd.h>
47 #include <linux/delay.h>
48 #include <asm/io.h>
49 
50 #define DRV_NAME	"rs5c313"
51 #define DRV_VERSION 	"1.13"
52 
53 #ifdef CONFIG_SH_LANDISK
54 /*****************************************************/
55 /* LANDISK dependence part of RS5C313                */
56 /*****************************************************/
57 
58 #define SCSMR1		0xFFE00000
59 #define SCSCR1		0xFFE00008
60 #define SCSMR1_CA	0x80
61 #define SCSCR1_CKE	0x03
62 #define SCSPTR1		0xFFE0001C
63 #define SCSPTR1_EIO	0x80
64 #define SCSPTR1_SPB1IO	0x08
65 #define SCSPTR1_SPB1DT	0x04
66 #define SCSPTR1_SPB0IO	0x02
67 #define SCSPTR1_SPB0DT	0x01
68 
69 #define SDA_OEN		SCSPTR1_SPB1IO
70 #define SDA		SCSPTR1_SPB1DT
71 #define SCL_OEN		SCSPTR1_SPB0IO
72 #define SCL		SCSPTR1_SPB0DT
73 
74 /* RICOH RS5C313 CE port */
75 #define RS5C313_CE	0xB0000003
76 
77 /* RICOH RS5C313 CE port bit */
78 #define RS5C313_CE_RTCCE	0x02
79 
80 /* SCSPTR1 data */
81 unsigned char scsptr1_data;
82 
83 #define RS5C313_CEENABLE    __raw_writeb(RS5C313_CE_RTCCE, RS5C313_CE);
84 #define RS5C313_CEDISABLE   __raw_writeb(0x00, RS5C313_CE)
85 #define RS5C313_MISCOP      __raw_writeb(0x02, 0xB0000008)
86 
87 static void rs5c313_init_port(void)
88 {
89 	/* Set SCK as I/O port and Initialize SCSPTR1 data & I/O port. */
90 	__raw_writeb(__raw_readb(SCSMR1) & ~SCSMR1_CA, SCSMR1);
91 	__raw_writeb(__raw_readb(SCSCR1) & ~SCSCR1_CKE, SCSCR1);
92 
93 	/* And Initialize SCL for RS5C313 clock */
94 	scsptr1_data = __raw_readb(SCSPTR1) | SCL;	/* SCL:H */
95 	__raw_writeb(scsptr1_data, SCSPTR1);
96 	scsptr1_data = __raw_readb(SCSPTR1) | SCL_OEN;	/* SCL output enable */
97 	__raw_writeb(scsptr1_data, SCSPTR1);
98 	RS5C313_CEDISABLE;	/* CE:L */
99 }
100 
101 static void rs5c313_write_data(unsigned char data)
102 {
103 	int i;
104 
105 	for (i = 0; i < 8; i++) {
106 		/* SDA:Write Data */
107 		scsptr1_data = (scsptr1_data & ~SDA) |
108 				((((0x80 >> i) & data) >> (7 - i)) << 2);
109 		__raw_writeb(scsptr1_data, SCSPTR1);
110 		if (i == 0) {
111 			scsptr1_data |= SDA_OEN;	/* SDA:output enable */
112 			__raw_writeb(scsptr1_data, SCSPTR1);
113 		}
114 		ndelay(700);
115 		scsptr1_data &= ~SCL;	/* SCL:L */
116 		__raw_writeb(scsptr1_data, SCSPTR1);
117 		ndelay(700);
118 		scsptr1_data |= SCL;	/* SCL:H */
119 		__raw_writeb(scsptr1_data, SCSPTR1);
120 	}
121 
122 	scsptr1_data &= ~SDA_OEN;	/* SDA:output disable */
123 	__raw_writeb(scsptr1_data, SCSPTR1);
124 }
125 
126 static unsigned char rs5c313_read_data(void)
127 {
128 	int i;
129 	unsigned char data = 0;
130 
131 	for (i = 0; i < 8; i++) {
132 		ndelay(700);
133 		/* SDA:Read Data */
134 		data |= ((__raw_readb(SCSPTR1) & SDA) >> 2) << (7 - i);
135 		scsptr1_data &= ~SCL;	/* SCL:L */
136 		__raw_writeb(scsptr1_data, SCSPTR1);
137 		ndelay(700);
138 		scsptr1_data |= SCL;	/* SCL:H */
139 		__raw_writeb(scsptr1_data, SCSPTR1);
140 	}
141 	return data & 0x0F;
142 }
143 
144 #endif /* CONFIG_SH_LANDISK */
145 
146 /*****************************************************/
147 /* machine independence part of RS5C313              */
148 /*****************************************************/
149 
150 /* RICOH RS5C313 address */
151 #define RS5C313_ADDR_SEC	0x00
152 #define RS5C313_ADDR_SEC10	0x01
153 #define RS5C313_ADDR_MIN	0x02
154 #define RS5C313_ADDR_MIN10	0x03
155 #define RS5C313_ADDR_HOUR	0x04
156 #define RS5C313_ADDR_HOUR10	0x05
157 #define RS5C313_ADDR_WEEK	0x06
158 #define RS5C313_ADDR_INTINTVREG	0x07
159 #define RS5C313_ADDR_DAY	0x08
160 #define RS5C313_ADDR_DAY10	0x09
161 #define RS5C313_ADDR_MON	0x0A
162 #define RS5C313_ADDR_MON10	0x0B
163 #define RS5C313_ADDR_YEAR	0x0C
164 #define RS5C313_ADDR_YEAR10	0x0D
165 #define RS5C313_ADDR_CNTREG	0x0E
166 #define RS5C313_ADDR_TESTREG	0x0F
167 
168 /* RICOH RS5C313 control register */
169 #define RS5C313_CNTREG_ADJ_BSY	0x01
170 #define RS5C313_CNTREG_WTEN_XSTP	0x02
171 #define RS5C313_CNTREG_12_24	0x04
172 #define RS5C313_CNTREG_CTFG	0x08
173 
174 /* RICOH RS5C313 test register */
175 #define RS5C313_TESTREG_TEST	0x01
176 
177 /* RICOH RS5C313 control bit */
178 #define RS5C313_CNTBIT_READ	0x40
179 #define RS5C313_CNTBIT_AD	0x20
180 #define RS5C313_CNTBIT_DT	0x10
181 
182 static unsigned char rs5c313_read_reg(unsigned char addr)
183 {
184 
185 	rs5c313_write_data(addr | RS5C313_CNTBIT_READ | RS5C313_CNTBIT_AD);
186 	return rs5c313_read_data();
187 }
188 
189 static void rs5c313_write_reg(unsigned char addr, unsigned char data)
190 {
191 	data &= 0x0f;
192 	rs5c313_write_data(addr | RS5C313_CNTBIT_AD);
193 	rs5c313_write_data(data | RS5C313_CNTBIT_DT);
194 	return;
195 }
196 
197 static inline unsigned char rs5c313_read_cntreg(void)
198 {
199 	return rs5c313_read_reg(RS5C313_ADDR_CNTREG);
200 }
201 
202 static inline void rs5c313_write_cntreg(unsigned char data)
203 {
204 	rs5c313_write_reg(RS5C313_ADDR_CNTREG, data);
205 }
206 
207 static inline void rs5c313_write_intintvreg(unsigned char data)
208 {
209 	rs5c313_write_reg(RS5C313_ADDR_INTINTVREG, data);
210 }
211 
212 static int rs5c313_rtc_read_time(struct device *dev, struct rtc_time *tm)
213 {
214 	int data;
215 	int cnt;
216 
217 	cnt = 0;
218 	while (1) {
219 		RS5C313_CEENABLE;	/* CE:H */
220 
221 		/* Initialize control reg. 24 hour */
222 		rs5c313_write_cntreg(0x04);
223 
224 		if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
225 			break;
226 
227 		RS5C313_CEDISABLE;
228 		ndelay(700);	/* CE:L */
229 
230 		if (cnt++ > 100) {
231 			dev_err(dev, "%s: timeout error\n", __func__);
232 			return -EIO;
233 		}
234 	}
235 
236 	data = rs5c313_read_reg(RS5C313_ADDR_SEC);
237 	data |= (rs5c313_read_reg(RS5C313_ADDR_SEC10) << 4);
238 	tm->tm_sec = bcd2bin(data);
239 
240 	data = rs5c313_read_reg(RS5C313_ADDR_MIN);
241 	data |= (rs5c313_read_reg(RS5C313_ADDR_MIN10) << 4);
242 	tm->tm_min = bcd2bin(data);
243 
244 	data = rs5c313_read_reg(RS5C313_ADDR_HOUR);
245 	data |= (rs5c313_read_reg(RS5C313_ADDR_HOUR10) << 4);
246 	tm->tm_hour = bcd2bin(data);
247 
248 	data = rs5c313_read_reg(RS5C313_ADDR_DAY);
249 	data |= (rs5c313_read_reg(RS5C313_ADDR_DAY10) << 4);
250 	tm->tm_mday = bcd2bin(data);
251 
252 	data = rs5c313_read_reg(RS5C313_ADDR_MON);
253 	data |= (rs5c313_read_reg(RS5C313_ADDR_MON10) << 4);
254 	tm->tm_mon = bcd2bin(data) - 1;
255 
256 	data = rs5c313_read_reg(RS5C313_ADDR_YEAR);
257 	data |= (rs5c313_read_reg(RS5C313_ADDR_YEAR10) << 4);
258 	tm->tm_year = bcd2bin(data);
259 
260 	if (tm->tm_year < 70)
261 		tm->tm_year += 100;
262 
263 	data = rs5c313_read_reg(RS5C313_ADDR_WEEK);
264 	tm->tm_wday = bcd2bin(data);
265 
266 	RS5C313_CEDISABLE;
267 	ndelay(700);		/* CE:L */
268 
269 	return 0;
270 }
271 
272 static int rs5c313_rtc_set_time(struct device *dev, struct rtc_time *tm)
273 {
274 	int data;
275 	int cnt;
276 
277 	cnt = 0;
278 	/* busy check. */
279 	while (1) {
280 		RS5C313_CEENABLE;	/* CE:H */
281 
282 		/* Initiatlize control reg. 24 hour */
283 		rs5c313_write_cntreg(0x04);
284 
285 		if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
286 			break;
287 		RS5C313_MISCOP;
288 		RS5C313_CEDISABLE;
289 		ndelay(700);	/* CE:L */
290 
291 		if (cnt++ > 100) {
292 			dev_err(dev, "%s: timeout error\n", __func__);
293 			return -EIO;
294 		}
295 	}
296 
297 	data = bin2bcd(tm->tm_sec);
298 	rs5c313_write_reg(RS5C313_ADDR_SEC, data);
299 	rs5c313_write_reg(RS5C313_ADDR_SEC10, (data >> 4));
300 
301 	data = bin2bcd(tm->tm_min);
302 	rs5c313_write_reg(RS5C313_ADDR_MIN, data );
303 	rs5c313_write_reg(RS5C313_ADDR_MIN10, (data >> 4));
304 
305 	data = bin2bcd(tm->tm_hour);
306 	rs5c313_write_reg(RS5C313_ADDR_HOUR, data);
307 	rs5c313_write_reg(RS5C313_ADDR_HOUR10, (data >> 4));
308 
309 	data = bin2bcd(tm->tm_mday);
310 	rs5c313_write_reg(RS5C313_ADDR_DAY, data);
311 	rs5c313_write_reg(RS5C313_ADDR_DAY10, (data>> 4));
312 
313 	data = bin2bcd(tm->tm_mon + 1);
314 	rs5c313_write_reg(RS5C313_ADDR_MON, data);
315 	rs5c313_write_reg(RS5C313_ADDR_MON10, (data >> 4));
316 
317 	data = bin2bcd(tm->tm_year % 100);
318 	rs5c313_write_reg(RS5C313_ADDR_YEAR, data);
319 	rs5c313_write_reg(RS5C313_ADDR_YEAR10, (data >> 4));
320 
321 	data = bin2bcd(tm->tm_wday);
322 	rs5c313_write_reg(RS5C313_ADDR_WEEK, data);
323 
324 	RS5C313_CEDISABLE;	/* CE:H */
325 	ndelay(700);
326 
327 	return 0;
328 }
329 
330 static void rs5c313_check_xstp_bit(void)
331 {
332 	struct rtc_time tm;
333 	int cnt;
334 
335 	RS5C313_CEENABLE;	/* CE:H */
336 	if (rs5c313_read_cntreg() & RS5C313_CNTREG_WTEN_XSTP) {
337 		/* INT interval reg. OFF */
338 		rs5c313_write_intintvreg(0x00);
339 		/* Initialize control reg. 24 hour & adjust */
340 		rs5c313_write_cntreg(0x07);
341 
342 		/* busy check. */
343 		for (cnt = 0; cnt < 100; cnt++) {
344 			if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
345 				break;
346 			RS5C313_MISCOP;
347 		}
348 
349 		memset(&tm, 0, sizeof(struct rtc_time));
350 		tm.tm_mday 	= 1;
351 		tm.tm_mon 	= 1 - 1;
352 		tm.tm_year 	= 2000 - 1900;
353 
354 		rs5c313_rtc_set_time(NULL, &tm);
355 		printk(KERN_ERR "RICHO RS5C313: invalid value, resetting to "
356 				"1 Jan 2000\n");
357 	}
358 	RS5C313_CEDISABLE;
359 	ndelay(700);		/* CE:L */
360 }
361 
362 static const struct rtc_class_ops rs5c313_rtc_ops = {
363 	.read_time = rs5c313_rtc_read_time,
364 	.set_time = rs5c313_rtc_set_time,
365 };
366 
367 static int rs5c313_rtc_probe(struct platform_device *pdev)
368 {
369 	struct rtc_device *rtc = rtc_device_register("rs5c313", &pdev->dev,
370 				&rs5c313_rtc_ops, THIS_MODULE);
371 
372 	if (IS_ERR(rtc))
373 		return PTR_ERR(rtc);
374 
375 	platform_set_drvdata(pdev, rtc);
376 
377 	return 0;
378 }
379 
380 static int __devexit rs5c313_rtc_remove(struct platform_device *pdev)
381 {
382 	struct rtc_device *rtc = platform_get_drvdata( pdev );
383 
384 	rtc_device_unregister(rtc);
385 
386 	return 0;
387 }
388 
389 static struct platform_driver rs5c313_rtc_platform_driver = {
390 	.driver         = {
391 		.name   = DRV_NAME,
392 		.owner  = THIS_MODULE,
393 	},
394 	.probe 	= rs5c313_rtc_probe,
395 	.remove = __devexit_p( rs5c313_rtc_remove ),
396 };
397 
398 static int __init rs5c313_rtc_init(void)
399 {
400 	int err;
401 
402 	err = platform_driver_register(&rs5c313_rtc_platform_driver);
403 	if (err)
404 		return err;
405 
406 	rs5c313_init_port();
407 	rs5c313_check_xstp_bit();
408 
409 	return 0;
410 }
411 
412 static void __exit rs5c313_rtc_exit(void)
413 {
414 	platform_driver_unregister( &rs5c313_rtc_platform_driver );
415 }
416 
417 module_init(rs5c313_rtc_init);
418 module_exit(rs5c313_rtc_exit);
419 
420 MODULE_VERSION(DRV_VERSION);
421 MODULE_AUTHOR("kogiidena , Nobuhiro Iwamatsu <iwamatsu@nigauri.org>");
422 MODULE_DESCRIPTION("Ricoh RS5C313 RTC device driver");
423 MODULE_LICENSE("GPL");
424 MODULE_ALIAS("platform:" DRV_NAME);
425